Quoted your entire email Tom W8JI..... did you say what SDR ...??
I think the problem here is some people read this as a SDR radios never
overload, or are superior in every case.
Apparently one person thought they were junk because multiple modest
strength signals would add up to overload them, and that triggered the
response that was misinterpreted to mean they never overload under any
condition or were always superior to roofing filtered systems common in
standard receivers.
In the case I had here, a *single* transmitter totally wiped the SDR out.
The overload was nothing like the desense or noise in a traditional
receiver. It just was totally useless. It was useless at any signal spacing,
because it had no front end selectivity at all that would reduce levels.
For my application, it was useless. It was far worse than a K3, which a few
kHz spacing would duplex on most antenna combinations. When the K3 (or
FT1000MP MKV's) did overload, the overload was a desense or composite noise
type sound. It would take out noise floor signals worse, be progressively
less problem for stronger signals, and never be bothered with any antenna
combinations with strong signals. When the SDR overloaded, it was just
totally gone for everything, and wider frequency spacing with the local TX
made absolutely no difference like it does with a normal receiver. I assume
this was from overflowing the ADC, but it was a very dramatic sounding
overload.
That, coupled with the fact it did not have a traditional knob and panel
system and had some transmitter spurs, made it useless here. But that was
this setup and this application, where a local 1500 watt transmitter within
a few thousand feet of the RX antennas was being used while receiving. This
was a single transmitter multi-op, where one TX signal was allowed on the
air at a time but two or more operators were making contacts.
I still never find any SDR I listened to, even that one without a
transmitter running, better than analog detection for my ears on
"in-the-noise" signals.
73 Tom
End of reading skills ---
Im looking for the SDR and the systematic objective testing procedure used in
the email ....
> From: w8ji@w8ji.com
> To: patriot121@msn.com
> Subject: Re: Topband: ADC Overload from MW transmitters
> Date: Tue, 20 Oct 2015 05:53:59 -0400
>
> > Tom never mentioned what type of SDR would be wiped out by moderate
> > signals ...
>
>
> Your reading skills must be near zero.
>
>
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